A new NDT technique for quality control of layered structures which is based on the interaction of laser light and ultrasound has been developed at the Department of Metallurgy and Materials Engineering in collaboration with the Interdisciplinary Research Centre (KULAK) of the Katholieke Universiteit Leuven. This new technique, which interrogates the material in a critical angle of ultrasound, measures the phase of the ultrasound reflected on the material. This paper focuses on the latest development of this technique and presents a sensor which combines the laser light and ultrasound within one device that can be mounted on any classical scanning device. This technique scans the material in the critical angle of ultrasound and a procedure has also been developed to scan for this angle automatically. These developments make the acousto-optic technique more robust, much more simple and efficient. The results using this new sensor are presented and compared with former results obtained in a set-up where laser light and ultrasound were separately mounted on an optical bench for stability purposes.